


a human pulse, its beat divine

by whaleandjanuary



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Bittersweet Ending, Exactly one kiss, M/M, Male My Unit | Byleth, Pre-Timeskip | Academy Phase (Fire Emblem: Three Houses), Spoilers for Post-Timeskip | War Phase (Fire Emblem: Three Houses), Unresolved Sexual Tension
Language: English
Status: Completed
Published: 2021-01-01
Updated: 2021-01-01
Packaged: 2021-03-11 10:16:04
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,238
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28469658
Author URL: https://archiveofourown.org/users/whaleandjanuary/pseuds/whaleandjanuary
Summary: The night before the Battle of Garreg Mach, Byleth worries about the future. Claude provides a mystery and a distraction.
Relationships: My Unit | Byleth/Claude von Riegan
Comments: 16
Kudos: 39





	a human pulse, its beat divine

**Author's Note:**

> This is pre-timeskip, at the tail end of when Claude would still be Byleth's student. Also this ends on kind of an ambiguous note. May the future be brighter.

It was the last night before the end of the world, and Byleth couldn't sleep. He was consumed with worries both petty and divine. Edelgard's army was _so_ large, a dozen times larger than any he'd ever faced. His students - his friends - were looking to him to save the day. _Rhea_ was looking to him to save the day. But he wasn't certain they could win, much less keep everyone alive. He could only have so many strategies fail before he couldn't rewind time anymore, and then not even Sothis would be able to save them. 

Byleth stood, because tossing and turning was doing him no good, and maybe pacing the room would tire him out properly. He caught a glimpse of himself in his mirror and turned to look. He frowned at the bags under his eyes, at his stupid green hair. 

He hated it, both because it was a constant reminder of Sothis's death, and because, selfishly, he didn't like the color. He'd _liked_ the blue, even though he hadn't realized it until he'd lost it. He'd briefly thought of dyeing it, but no. To everyone else, the hair was a symbol of divine blessing, and he needed to give people hope. 

Even if he had little himself. 

But that was his own damn fault. He'd lost his closest friend - his first, really - because of his own stupid impulsiveness. He'd charged off at the first hint of a chance to avenge his father. Like a fool. Like an _amateur._ And Sothis had paid for it with her life. 

And Byleth had paid for it with... not his sanity, per se, but his balance? Everything was too bright and too loud now. He found himself getting angry or sad in flashes constantly. It wasn't that he hadn't felt things before, but it had been slow, considered. He'd have been able to sleep, before. He'd have felt worried, sure. But he'd look at the worry, declare it not worth losing sleep over, and go to bed. Or at the very least, Sothis would have told him that things would be ok. 

Even with his father, that had been a singular event, the exception that proved the rule. He'd sobbed until his eyes hurt, until his throat ached, but his world had just been utterly destroyed in front of him. Of course it took time to heal from that. 

Byleth caught a lock of hair between his fingers, lifted it, let it fall. Maybe he had always been changing. Maybe Sothis had simply made it happen faster. No matter the details, he supposed. He desperately wished she could give him advice. Even if she just said, "We'll get through it," that would be a comfort. 

He didn't want to be alone with his overwhelming emotions and his stupid hair and the burden of all the people who thought he had a solution that he had no idea how to find. 

Someone knocked on his doors. 

Byleth threw them open without thinking, and found Claude there, still fully dressed despite the late hour. Smiling, but... perhaps he was a little nervous. 

"Heya, Teach. Is it all right if I - are you ok?" 

Byleth froze, unsure what Claude was seeing in his face. "I'm thinking about tomorrow. I couldn't sleep." 

"Oh. Me too, actually, ha ha. Um." Claude exhaled. "Can I come in?" 

Byleth stepped back and motioned into the room. Claude entered, looked around for a moment, and sat on the bed. Byleth closed the doors. 

"Do you want to go over the plan for tomorrow?" Byleth asked. 

Claude shook his head. "No. We've been going over it for days. I... How do I put this...? There's a mystery I've been puzzling over, and if we're all going to die tomorrow, I really don't want it to be with this unsolved." 

"What mystery?" asked Byleth, slightly confused. He'd already explained what he knew of the darkness, right?" 

"Ok," said Claude, leaning forward and putting his elbows on his knees, "you know your father's diary, right? And the bit about how the baby has a pulse but no heartbeat? That sentence has been kind of driving me crazy, because your heartbeat is what makes your pulse happen. And even though I am perpetually disappointed by this sort of thing, I _thought_ that was common medical knowledge. But maybe your father miswrote what the doctor said. Or maybe it _is_ something weird." 

Claude waved his hands a bit, gathering himself. "Anyway, I have a theory, and I think you know what it is, but... Ok, this is awkward. Can I listen to your heartbeat?" 

"...Ok," said Byleth, and pulled off his sleep shirt. 

Claude's eyes went wide. "Oh. Ok... thanks." He stood and slowly walked around Byleth, lifting each of his arms in turn and staring intently. 

"Can you _see_ a heartbeat?" asked Byleth. It was strange, suddenly feeling like he was on display. He was slightly embarrassed about it. Why was he embarrassed about it? 

"Sorry!" said Claude, dropping Byleth's arm and jerking back. "I wasn't expecting you to take off your shirt, but since you did, I'm looking for scars." 

"I have a lot of scars." 

"I know. I'm looking for something particular, though. A line up your chest or back. An incision. Or a hole, maybe." 

Byleth raised his eyebrows in alarm. "Do you think Rhea took my heart _out?_ " 

"No, the opposite. Is it.. is it ok if I..." Claude tentatively held out a hand, as if he were pushing on an invisible wall. "... feel?" 

Byleth shrugged and then nodded. Claude liked being a mystery as much as he liked solving them. He'd make his point eventually. 

Claude put his palm on the center of Byleth's chest and dragged it down, fingertips pressing into his skin. It felt strange, but nice, like Claude was pouring heat into him. Claude repeated the gesture on Byleth's back, which caused him to shiver involuntarily. 

"Sorry, Teach," murmured Claude. 

"It's ok. Do you see what you're looking for?" 

"Just... battle scars." Claude sighed and Byleth felt both of his hands on his shoulder blades. "I'm just gonna - I might as well be thorough while I'm here." 

Claude passed his hands over the rest of Byleth's torso, catching his fingertips on a number of old wounds. 

"My face feels hot," said Byleth, touching his cheek. Claude was facing him, hands on Byleth's waist. It tickled slightly, but not enough for Byleth to tell him to move. 

"Yeah, Teach. You're a bit red." 

"So are you." 

"No I'm n- well, your room's kind of hot, Teach." Claude dropped his hands. His voice was pitched upward in a way Byleth had never heard before. "Say, you keep the Sword of the Creator in here, right? Would you mind holding it?" 

"Ok," said Byleth, as Claude spun around the room and took the sword out of its corner. Sothis's corner. 

Claude lovingly ran a hand down the center of the blade. "You never could have been mine, after all," he said, quietly. Then he handed the sword to Byleth and it flared with a familiar red light. 

"Right. The sword lights up too. Hm..." Claude pulled the blanket off the bed and tossed it over Byleth's arm and the weapon both. Then he cupped his hands to make a circle on Byleth's chest, and stuck his face into the space they made. 

"Are you trying to see into my chest?" asked Byleth. "I don't think that works." 

"Shh. I'm trying to see if I can see it glowing." 

"See _what_ glowing?"

"The Crest stone, Teach!" Claude stepped back and clasped Byleth's shoulders. "Somehow, Rhea put the Crest stone of the Sword of the Creator into you, and it made you live, and I think it's acting as your heart." He shook Byleth slightly. "I know the _what_ but I don't know the _how_ , and not understanding it is _killing_ me." 

Claude abruptly bent down and pressed his ear against Byleth's chest. "I really _don't_ hear anything. Ugh. I should have lifted a stethoscope from Manuela. What was I thinking?" 

A thought flashed into Byleth's head that he should put his free arm around Claude, but he pushed it away. "I have a pulse. I can feel it in my wrists right now. It's... fast." 

Claude didn't move. "But you can't feel anything in your chest?" 

"No. Should I?" 

Claude stood. "A normal person would. But you have your own rules, Teach." He took the blanket and sword and put them back in their respective places. "Well, this is disappointing." 

Byleth held out his wrist. "Do you want to feel it?" 

Claude nodded, slowly. "Might as well." 

Claude took Byleth's wrist in one hand and pressed two fingers to the inside surface with the other. "Totally normal." He rubbed his thumb against Byleth's skin and stared down at the offending wrist. "You wouldn't know anything was unusual. I wonder how far from your heart the effect starts."

He snapped his eyes up to Byleth's face. "Do you mind if I, uh, check your neck?" Byleth tilted his head to give him room. 

"Ok," said Claude. He kept his hold on Byleth's wrist, but touched under Byleth's jaw, pushed in with his fingertips until he found what he was looking for. "It's normal here too." 

"With your hands like this, it feels like you're pulling me in for a dance," said Byleth. 

Claude laughed. "I did that once." 

"Yeah." Byleth smiled. "Can I listen to your heartbeat?" He pointed to Claude's chest. "I don't know what it's supposed to sound like."

"Oh, I... sure, Teach. Listen away." Claude rubbed the back of his neck as Byleth leaned down to listen. 

"I don't hear anything. Are you sure I should hear something?" 

"You can't hear through my clothes, I bet. Let me take my coat off." Claude bit his lower lip and started unfastening things. 

"You're overheating again," said Byleth. 

"Hah! Well, good thing I'm taking my coat off then!" Claude tossed it over Byleth's desk chair. He held his shirt at the waist and pulled it up to his chin. 

"Here you go. Heart's all yours." He winced. 

Byleth leaned down and pressed his ear to Claude's chest. Claude was shaking slightly, but he relaxed as Byleth listened. 

_thump-thump, thump-thump..._

"Ohhh," said Byleth. "Like a giant pulse." 

"Yeah. That's basically what it is." 

"Is it supposed to be that fast?" 

Claude inhaled unsteadily, then said, "Yes."

So curious. Byleth stood up straight again. "And it's exactly the same here?" He touched Claude's neck. 

"Wrong place." Claude put his hand over Byleth's and adjusted the position of his fingers. "Here..." Claude put his other hand under Byleth's jaw. "Like this." 

"I can feel it now." Byleth smiled again. He could feel Claude's pulse and Claude could feel his. Like a circle. 

Claude was very slightly taller than Byleth like this, because he was still wearing his boots. But it was easy to look into his eyes. It was harder to read the expression in them. It was something Byleth had never seen before. 

"Hey, Teach? Can you do me a favor? Can you close your eyes for a sec?" 

"Ok," said Byleth, doing so. "W-"

Then Claude's lips were on his. 

Byleth had no frame of reference for this. It wasn't that he didn't know what kissing was. He just had no first-hand experience with it. What he learned immediately was that he liked it, and he wanted Claude to keep doing it. 

Claude slid his hand around to the back of Byleth's neck, and it felt comforting and exciting at the same time. Byleth put his hands on Claude's waist and pulled him in until they were touching. Claude's shirt was still half-pulled-up and the touch of his skin felt magical somehow. Byleth's pulse was pounding in his throat. 

Claude said something - no, he made a wordless noise, like he was tasting something delicious. Claude parted his lips slightly, and Byleth matched him with a sigh. The blood was so loud in Byleth's ears. Claude slid his tongue into Byleth's mouth, and Byleth clutched at him, dizzy and afraid he might somehow fall. Claude put his hand on Byleth's cheek, and Byleth made another, desperate sound. 

Claude pulled away, so suddenly there was a slight smack of their lips separating. He looked stricken. "We can't do this." 

"I'm sorry," said Byleth, putting a hand over his mouth. He didn't know what he'd done wrong, but Claude was clearly upset. 

"No, it's - I want - I - " Claude rubbed a hand over his face and returned to that neutral smiling-mask expression he wore so often. Byleth's organs felt like they were all falling over inside him. "We can't do this now." Claude was putting his coat back on. "I don't want anybody dying because they weren't rested for battle, and that includes us."

Byleth nodded silently. 

"Tomorrow." Claude put his hand on Byleth's cheek again. It was shaking. "After the battle. Tomorrow night. I'll come back here again." He gave a little laugh. "Incentive for both of us to not die, right?" 

"Ok," said Byleth, instead of _I am definitely not going to sleep now._

Claude paused at the door. "Goodnight, T - goodnight, Byleth." Then he was gone. 

Byleth sat down on the bed, and had completely different things to worry about. 

_And five years is such a very long time..._


End file.
